Extensive human impact in south western Australia has resulted in a high incidence of rarity throughout the highly endemic flora of the region. Grevillea scapigera (Proteaceae) is a typical example, with 27 plants (represented by four extant populations) remaining in the wild. In order to devise an appropriate strategy for the conservation of this species, its population genetics were studied using RAPD analysis, which enabled the discrimination of individual plants and the detection of a relatively high amount of variability (V = 0.32) within G. scapigera. This variability was found to be evenly distributed within the plants analysed despite the clear distinction between most populations (87% of the variability being attributable to single plant difference and 13% to population difference). Finally, RAPD analysis was used to select a small group of plants that captured maximum genetic variability to be used in the recovery program of the species. Because of the low genetic difference between populations, the mixing of these selected plants during the recovery process should not create genetic imbalances. The methods used in this study provide a useful model for future projects involving the recovery of rare flora.

It was shown that the development of liver glucokinase in the rat coincided with a peak in the levels of circulating thyroid hormone at about the 16th postnatal day. Administration of thyroid inhibitors blocked the development of the enzyme and administration of thyroid hormone restored activity to normal levels. Glucokinase could be induced prematurely as early as the 2nd postnatal day by the administration of thyroid hormone followed by daily injection of glucose (10 mg/g body weight). Glucocorticoids and corticotropin failed to induce glucokinase activity prematurely. The postnatal increase in circulating thyroid hormone levels together with increased intake of carbohydrate at weaning may be the normal physiological stimulus for induction of this enzyme.

The relationship between the induction of hepatic phosphopyruvate carboxylase activity and the incorporation in vivo of ¹⁴C from lactate into glucose and glycogen was determined in rats during the first 6 h after surgical delivery. Phosphopyruvate carboxylase activity and gluconeogenic capacity were extremely low at the time of delivery. After the first hour phosphopyruvate carboxylase increased markedly, but the development of gluconeogenesis lagged behind that of the enzyme and increased slowly during the first 2 h. Thereafter it increased rapidly in an almost linear manner. The administration of actinomycin D at delivery prevented the synthesis of glucose and glycogen 4 and 6 h later. If phosphopyruvate carboxylase had previously been induced in utero, the animals were unable to synthesize glucose and glycogen immediately after delivery, but the postnatal development of the process was very rapid with only a slight lag.

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